Femtosecond lasers are presently used in a wide variety of applications. One common application of these devices is biological research, such as bio-imaging, two-photon microscopy, medical diagnostics, vision correction, the study and applications of light-tissue interactions, and the like. The use and applicability of femtosecond lasers accelerated after the development of turn-key Ti:sapphire oscillators, which were a major advancement from the point of view of performance and ease of use.
Typically, biological research and related applications require that the laser system offers:                (A) High peak power: many applications based on nonlinear light-matter interactions require high laser intensity. High peak power (>100 kW) requires high pulse energy and short pulse durations;        (B) High repetition rates: enable high acquisition rates with excellent averaging (low noise). For a laser pumped with limited pump power the demands of high peak power and high repetition rates are contradictory since the pulse energy is given by the (limited) output average power divided by the repetition rate;        (C) Pulse durations within a desired range: shorter pulses result in higher peak power. However very short pulses (<25 fs) require expensive dispersion management add-ons to balance the temporal dispersion produced by application-dependent accessories (microscope objectives, modulators etc.). Very short pulses also require very large spectral bandwidths, which in turn require expensive optical elements. Large spectral bandwidths can be harmful for applications where wavelength selectivity is desirable. As a consequence pulses in the 50 fs-100 fs range are preferred; and        (D) Lasing wavelength within a desired range: most biological materials and bio-research materials interact efficiently with light only at specific wavelengths. For example one of the most widely used dye markers, the green fluorescent protein (GFP), requires an excitation wavelength of 900 nm-980 nm.        
As a result, a laser system for biological research applications needs to be designed to optimally balance the above-referenced performance needs. Generally, presently available commercial Ti:sapphire oscillators significantly exceed the performance requirements for most biological research applications, especially the output power levels. Despite the excellent performance of Ti:sapphire oscillators a number of shortcomings have been identified. For example Ti:sapphire oscillators tend to be large, expensive, and complex systems. For example, presently available Ti:sapphire oscillators require a complex multi-stage laser pump system which includes a pump laser and a diode pump source. More specifically, the first stage of the pump system comprises a diode laser system which is used to provide a first pump signal to the pump laser. The second stage of the pump system comprises a pump laser which, in response to the first pump signal, produces a second pump signal. The second pump signal from the pump laser is directed into the Ti:sapphire laser system which produces an output signal. As such, the presently available Ti:sapphire laser systems includes the Ti:sapphire laser device, at least one pump laser source to pump the Ti:sapphire laser, and at least one diode pump source to pump the pump laser system.
In light of the foregoing, there is an ongoing need for a simpler, smaller and lower cost laser system which is capable of delivering the performance characteristics for biological research applications. There is an additional need for a compact and lower cost seed laser for Ti:sapphire amplifier systems that produces pulses of sufficiently short duration.